The ear canal is generally narrow and tortuous with dimensions, and may vary significantly among individuals. Placement of a miniature hearing device inside the ear canal is generally desirable for various electroacoustic advantages, such as reduction of the acoustic occlusion effect, improved energy efficiency, reduced distortion, reduced receiver vibrations, and improved high frequency response. Canal placement may also be desirable for cosmetic reasons since many of the hearing impaired may prefer to wear an inconspicuous hearing device. A canal hearing device can be inserted entirely or partially inside the ear canal. In the context of this application, any hearing device inserted inside the ear canal, whether partially or completely, may be referred to as a canal hearing device. This includes what is known in the hearing aid industry as Completely In the Canal (CIC), In-The-Canal (ITC), and extended wear deep canal invisible types. A canal hearing device is generally elongate with a longitudinal axis, having a medial end (facing the eardrum) and lateral end for access and manipulation.
Conventional batteries for canal hearing devices include zinc-air varieties, which are generally non-rechargeable, thus replaced frequently by the user. Given the advanced age of the average hearing aid user and diminutive size of canal hearing devices and their batteries, replacing the battery and/or manually switching off the canal hearing device are often inconvenient and frustrating tasks for the user due to the user's decreased dexterity and possible vision impairment. The present invention describes examples of modular hearing aid designs, tools, and methods which may address some of these shortcomings.